228 Annals of the South African Museum. 



Ptychomya; Thetironia ; Anthony a ; Solecurtus, and Meyeria. 

 Further, there is found to be no support whatever for the suggestion 

 occasionally put forth, that the Uitenhage Marine Beds may cor- 

 respond to a part of both the Upper Jurassic and the Lower 

 Cretaceous series of Europe. So far as the palaeontological evidence 

 goes, there appears to be every probability that the strata yielding 

 the marine fossils were deposited with comparatively great rapidity, 

 and there is no indication of such diversity in the character of the 

 fauna as would be consistent with the supposition that more than 

 the equivalent of one palaeontological stage is represented. Some of 

 the typical marine forms are now known to have a much more 

 extensive vertical range in the series than was formerly suspected, 

 and the sameness of character in the fauna observed at different 

 levels in the series seems to preclude any attempt to establish zonal 

 divisions. It may be inferred that the Marine Beds were rapidly 

 accumulated, and that they represent a very restricted period of 

 time. 



Amongst the Uitenhage Mollusca, the Gasteropoda constitute the 

 least important element in a comparative study, while the Cephalo- 

 poda furnish the most significant evidence by reason of their close 

 alliance with forms having well-restricted vertical range in Europe. 

 The Lamellibranchiata largely preponderate in the fauna, and 

 prominent amongst these are Trigonice, which represent divisions of 

 the genus as yet unknown to occur in Europe. While many of the 

 lamellibranchs afford data which are valuable in supporting the 

 evidence yielded by the Cephalopoda, in a correlation with European 

 standards, some of the best-characterised bivalves are of very great 

 interest from the fact that they and their close allies have an 

 extensive geographical distribution, and enable us to bring the 

 Uitenhage Series into broad correlation with deposits situated in 

 widely separated regions outside the European area. 



Correlation of the Fauna. A detailed comparison with the 

 Secondary faunas of Europe has shown that, despite the presence of 

 some few bivalve forms which not remotely resemble familiar Jurassic 

 types, there is abundant evidence in support of the opinion of those 

 German writers who have ascribed to the Uitenhage Series a Lower 

 Cretaceous age. Only a very small proportion of the Mollusca can 

 be definitely identified with European forms, but a considerable 

 number are closely comparable with Neocomian and Aptian shells. 

 This is true of many of the lamellibranchs, which nevertheless, as 

 might be expected, would alone afford comparatively scanty data for 

 a precise correlation of the Uitenhage beds with members of the 



